Thanks for trying to help, but as I wrote: 1) I just passed the data
2272 x 1704 size 35 mm focal 1 crop factor 2) I did not run the optimization process >From data in 1) Hugin computes 52.62 degrees Have you tried the test I proposed in the previous post ? On Apr 13, 5:52 am, "Ir. Hj. Othman bin Hj. Ahmad" <othm...@lycos.com> wrote: > Sorry for my earlier response. > > I'm not an authority on Hugin since I have not studied its source code > but since nobody is responding to your post, I can volunteer to > explain with my experience in numerical methods. > > Without any clue as to the FOV of an image, Hugin must have been hard > coded to give 35mm as the initial estimate, and it is a good value > indeed. The closer this estimate to the actual FOV, the faster pano > tools will optimise. Most pano pictures use wide angle lenses of at > most 35mm. > > On Apr 11, 2:55 pm, alf <liquidt...@gmail.com> wrote: > > > > > No. I didn't even run the optimization process. The fov I'm referring > > to was computed in the file dialog after loading the images. > > You can verify this by simply creating an image of size2272x1704 > > without exif data (simply save in PPM format for example) and upon > > loading it give it a focal length of35mm and a crop factor of1. > > Hugin automatically fills the fov entry box with52.62degrees. > > > On Apr11,5:17 am, "Ir. Hj. Othman bin Hj. Ahmad" <othm...@lycos.com> > > wrote: > > > > This data is from the optimisation process of the control points. > > > > This fov gives the least error in all the control points. > > > hugin or any numeral method systems, need to know the boundaries for > > > the fov or any data. In a360x180, it is360degrees horizontally and > > >180% vertically. > > > > So it is good if you have a set of pictures linked with control points > > > that wrap around vertically or horizontally. hugin will have > > > additional data to adjust fov. > > > > hugin can still minimise the errors by giving estimates to the fov but > > > these estimates may be completely wrong to a human being, but you can > > > help hugin by giving it the initial estimates for the fov for hugin to > > > quickly minimise the errors. > > > > On Apr9,9:27 pm, alf <liquidt...@gmail.com> wrote: > > > > > Hmmmm, so here's the data for my camera > > > > > width2272 > > > > height1704 > > > > focal length (35mm equivalent) 35mm > > > > > From this only data Hugin gives me52.62degrees of FOV : I can not > > > > understand where this number comes from > > > > > I tried the suggested Javascript with the same data and I get 176° > > > > of hfov ! Obviously wrong because the script needs data to be > > > > expressed in the same units (pixels), so the focal length should be in > > > > pixels (?) > > > > > On Apr9,2:36 pm, Harry van der Wolf <hvdw...@gmail.com> wrote: > > > > > > Hi, > > > > > > I can explain it to you, but if you take a look at > > > > > <http://imaginatorium.org/stuff/angle.htm>, you can do some > > > > > calculations for > > > > > yourself and see the calculation if you do a "view page source" (or > > > > > whatever > > > > > the command in your browser is). It is in the simple javascript where > > > > > you > > > > > can find how to calculate the FOV, both HFOV and VFOW, based on the > > > > > focal > > > > > length. > > > > > > Please note that this calculation is for a rectilinear lens. I don't > > > > > know > > > > > the calculation for a fisheye lens (don't have one, never bothered to > > > > > know). > > > > > I assume when you google you will find the answer soon enough. > > > > > > Harry > > > > > >2009/4/9alf <liquidt...@gmail.com> > > > > > > > I have some images without exif data, for which I know that the35mm > > > > > > equivalent focal length was...35mm. I've seen that Hugin with this > > > > > > data computes automatically a FOV when I input the images. How > > > > > > possible, if the only thing the software knows is the focal length > > > > > > and > > > > > > the image size in pixels ???? Can someone explain me how ? Thanks. --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "hugin and other free panoramic software" group. A list of frequently asked questions is available at: http://wiki.panotools.org/Hugin_FAQ To post to this group, send email to hugin-ptx@googlegroups.com To unsubscribe from this group, send email to hugin-ptx-unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/hugin-ptx -~----------~----~----~----~------~----~------~--~---
